Lifting-cylinder valve for forging-presses



I A. P. BARK. LIFTIEFJG CYUNDER VALVE FOR FORGlNG FBESSES.

APPLICATION FILED APR: 1!, I9I9.

Patented Jun 8, 192%..

2 SHEETSSHEET 1-- A. P. BARK.

LIFTING CYLINDER VALVE FOR FORGING PBESSES.

APPLICATION FILED APR. 11, 1919.

L343,02% Patented June 8, 1920-.

2 SHEETS-SHEET 2- FIG. 4 I

ARNOLD P. BARK, 0F PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO UNITED ENG-I-NEERING & FOUNDRY COMPANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORA- TIONOF PENNSYLVANIA.

LIFTING-CYLINDER VALVE FOR FORGING-IPRESSES.

Application filed April 11, 1919.

To all whom it may concern:

Be it known that I, ARNOLD P. BARK, a subject of the King of GreatBritain, and. resident of Pittsburgh, in the county of Allegheny andState of Pennsylvania, have invented a new and useful Improvement inLifting-Cylinder Valves for Forging- Presses; and I do hereby declarethe following to be a full, clear, and exact description thereof.

My invention relates to valves for steam hydraulic intensifier forgingpresses, which are employed for all characters of forging, pressing orshearing; and. especially to the valve gear for the lifting cylinders ofthe press head. These presses have been in large use and have been oflate years increased in size to provide for pressing strokes of manytons per square inch. They are controlled. by a single lever, in thehand of the operator, and it has been found that with the liftingcylinder valve heretofore used certain diliiculties arose when appliedto very large presses. These valves were liable to kick and suddenlyjump wide open, getting out of the operators control, and were alsoliable to hesitate in their downward travel.

Study of the problem has shown that in these large presses the suddenrush of partially condensed steam was liable to be so great and rapidthat the valve was forced upwardly before there was time for thepressure to equalize, and so imparted the kicking action above referredto; while the hesitating action was due to a loss of pressure betweenthe steam entering and leaving the valve chamber, so that the upwardpressure was greater than the downward pressure, for a short time duringwhich the steam was in rapid motion, and the valve was not perfectlybalanced. The object of the present invention is to overcome thesedifliculties, and this is accomplished in the manner hereafter describedand claimed, which can be better understood by a full description of theapparatus.

In the accompanying drawing, Figure 1 is a vertical section with partsin elevation of the lifting cylinder valve in its lowest position whenadmitting steam to the lifting cylinders. Fig. 2 is a like view of thevalve in raised position where the steam supply is cut off. Fig. 3 is avertical section partly Specification of Letters Patent.

Patented June 8, 11.920.

Serial No. 289,339.

broken away and at right angles to Fig. 2, showing especially the dashpot construction; and Fig. 4 is a diagran'nnatic view of a steamhydraulic forging press illustrating an approved construction to whichthe valve is applied.

in the diagrammatic view Fig. 4% the lifting cylinder valve is shown atQ, the steam entering at P and flowing through said valve and throughthe pipe R to the lifting cylinder or cylinders E which are connected tothe press head B, the forging die B of which operates upon the anvil 01'bottom die A, the press head. being mounted on the guides B The pistonsF are connected by the piston-rods G to the press head, the weight ofthe press head being sufficient to press back the steam through thevalve Q, the lower end of which connects with the exhaust pipe U. Thesteam inlet P connects with the main steam valve N leading to the steamintensifier cylinder J, the exhaust valve fron said cylinder being shownat T. The hydraulic ram K of the intensifier cylinder J operates in theram cylinder L and forces the waterthrough the hydraulic high pressurepipe M to the hydraulic cylinder D in which the main hydraulic ram0perates, said ram being connected to the press head 13. To maintain thehydraulic high pressure pipe full of water, the particular tank V isemployed. The operating or hand lever Y is connected to the operatinglever mechanism 2 for the steam intensifier, employing therein afloating link construction which does not require full description; Thislever Y operates through the trip gear construction X to take hold onthevalve stem 3 through the arm 4 for operating the valve Q. It seemsunnecessary to describe further the construction of the press as theinvention relates particularly to the lifting cylinder valve Q, which isillustrated in detail in Figs. 1 to 3. The valve casing 5 has the valvechamber 5 of uniform diameter, in which fits the valve member 6connected to the valve stem 3. The lower end of the valve chamber 5connects with the exhaust pipe U. In the upper part of the valve casingis the steam supply passage 7 which communicates with the valve chamberat 8 and the port 9 connects with the steam pipe R leading to thelifting cylinders E. It'will be seen that the main reciprocating valvemember 6 is hollow connecting with the valve chamber both above andbelow the valve to provide for balancing the same. In the constructionillustrated in the drawings, the valve 6 has the central reduced portion12 and below the same has the enlarged portion 13, fitting within thevalve chamber and traveling normally opposite the portion 1 1 diameterof the reduced portion 12 of the valve 6 decreases gradually from theupper portion 13 tov its mid-portion and thence it similarly increasesgradually as far as the abrupt shoulder 21 which forms the upper edge ofthe portion 13.

In the construction heretofore employed it was found that on the returnof the steam from the lifting cylinder the sudden rush of partiallycondensed steam was so great and rapid that the valve was forced upbefore there was time for the pressure to equalize, and this actionthrough the valve stem gave the sudden kick to the operating lever Y andwas liableto force it out of control. To overcome this difliculty, Ihave provided on the main reciprocating valve 6 the knob 16 projectingcentrally below the valve face 13 so that when the valve 6 is raised tothe position shown in Fig. 2, the outrushing steam from the liftingcylinders under the weight of the press head B impinges on this knob andretards the upward movement or jump or kick of the reciprocating valve6, preventing such sudden upward movement of the valve. As illustrated,in said Fig. 2, this knob projects downwardly within the valve chamberand its side walls 17 are gradually upwardly curved so that theoutrushing steam impinges against them and provides a downward holdingforce until the steam can rise through the hollow valve into the'upperportion of the valve chamber 5 and cause a better balance of'the valve.

It will be noted that the steam supply passage 7 leads downwardly on agradual curve to the port 8, the top and bottom walls of the port 8being both inclined downwardly as shown at 19 and 20 so as to projectthe entering steam from the passage 7 into the portion 14: of the valvechamber 5 in a downward direction. It will also be seen that the centralreduced portion 12 is curved or tapered gradually downward, having itssmaller" diameter adjacent to the valve portion 13, and terminates inthe upper face of the valve portion 13 of the reciprocating valve 6which is practically square or dished as at 21, so that the downwardlyrushing steam strikes against the abrupt top face 21 and acts by itsimpingement to force the valve downwardly, pressing on the same as thevalve portion 13 passes the port 9, when the steam escapes through thepipe R to the lifting cylinders. In the former construction, as abovestated, this valve was liable to hesitate in its downward movement, asthe steam from. the steam inlet struck horizontally against the valvebody maintaining a high pressure in the upper part of the portion 14 ofthe valve chamber and tending to lift the valve bypressure exerted onthe lower face of the valve portion corresponding to the portion 13 inthe present case, which, in previous constructions, was practicallysquare, while a lower pressure was exerted downwardly ona similar areawhen the valve was in the position shown in Fig. 3, thus throwing thevalve out of balance until the pressure in the inlet and outlet portsbecame equalized. By these changes in construction, I utilize theimpingement of the steam against the shoulder 21 to overcome thishesitation of the valve and to act upon it with sufficient force toobtain a positive movement of the valve downwardly.

Practical use has shown that more than sufficient force for thisoperation is obtained by such construction of the valve casing and valveand in order to control the valve, I provide a dash-pot 26, theconstruction of which is more particularly shown in Fig. 3. At the upperend of the valve casing is the supplemental chamber 24 through which thestem 3passes, and this stem carries the supplemental portion 25 playingtherein. The lower portion of this supplemental chamber forms a dash-pot26 more particularly shown in Fig. 3. The main valve chamber 5 connectswith the supplemental chamber 24 through the port 27 which leads intothe supplemental chamber some distance above the bottom of this chamber.At the bottom of this-chamber 2 1 is located the small port 28 whichcommunicates with the main valve chamber 5, through the port 29. Theseports are under the control of the choke valve 3O so that the control ofthe dash-potcan be accurately regulated to give the desired resistanceto the downward movement of the valve.

In the operation of the apparatus, as so described, steam passes throughthe valve Q, by the communicating ports 8 and 9 to the lifting cylinderor cylinders E, lVhen it is desired to cut off the steam supply thevalve 6 is lifted and in its further upward movement for the purpose ofreversing the direction of travel of the press-head, the steam' from thecylinder E exhausts suddenly, striking against the knob 16 and by itsimpingement overcomes any rapid rise of the valve under the unbalancedpressure and overcomes the liability of kicking, as the valve quicklybecomes balanced and re mains within the operators control. In thisaction the steam strikes on the upwardly inclined faces 17 of the knoband provides the necessary retardation. When it is desired to opencommunication between the steam supply passage 7 and the cylinders, asthe operator starts the downward movement of the valve, the steam fromthe supply pipe overcomes the hesitation of the valve by striking in adownward direction from the downwardly inclined port 8 with itsdownwardlyinclined sides 19 and 20 leading from the steam supply passageto the main valve chamber and by contacting with the abrupt valve face21 and so develops suilicient power to give the necessary desiredmovement. In case this movement is greater than required, and in orderto cushion the downward movement of the valve, the steam, under thenormal back pressure which exists within the valve chamber 5 by reasonof the fact that the entire steam line is constantly filled with steamunder pressure, enters through the port 27 into the lower portion 26 ofthe supplemental chamber 2% and acts to retard sudden movement. When thevalve 25 passes the inlet of said port27 into the supplemental valvechamber the confined steam is choked in the dash-pot 26 and the downwardmovement of the valve is checked according to the adjustment of thechoke valve 30. Thus, I am enabled to obtain a steady movement of theparts and an easy hand control of the operating lever Y, even in valvesof large dimensions.

In the above specification I have described the position of the valve asillustrated in the drawing. It is to be understood, however, that theposition of the parts is relative and the description and claimsapply tothe valve placed in the positions shown, and are intended to cover theapparatus broadly to perform the special functions aimed at.

That I claim is:

1. In a valve for steam hydraulic presses, the combination with thevalve casing having ports leading from the steam supply, to the liftingcylinder, and to the exhaust, of a reciprocating valve in said casingcontrolling said port to the lifting cylinder, said valve being providedwith a central knob at one end to receive the impinging steam from thelifting cylinder and to balance the pressure on the valve.

2. In a. valve for steam hydraulic presses, the combination with thevalve casing having ports leading from the steam supply and to thelifting cylinder, and to the exhaust, of

a hollow reciprocatingvalve therein controlling said port to the liftingcylinder, and provided with a central knob below the central hollowportion at one end to receive the impinging steam from the liftingcylinder and balance the pressure on the valve.

3. In a valve for steam hydraulic presses, the combination with thevalve casing having ports leading from the steam supply and to thelifting cylinder, and to the exhaust, of a reciprocating valve thereincontrolling the port to the lifting cylinder and provided with a centralknobat one end having gradually upwardly receiving side walls to receivethe impinging steam from the lifting cylinder and balance the pressureon the valve.

4. In a valve for steam hydraulic presses, the combination with a valvecasing having a valve chamber of uniform diameter, and an admission portfrom the steam supply provided with downwardly extending port walls, aport leading to the lifting cylinder, and a valve therein having areduced portion opposite the steam supply port, and enlarged to fullsize of the valve chamber and. provided with an abrupt shoulder belowthe reduced. portion, substantially for the purposes set. forth.

5. In a valve for steam hydraulic presses, the combination with valvecasing, having a valve chamber of uniform diameter and a steam supplyadmission port 8 provided with the downwardly extending walls 19 and 20,and a valve therein having a reduced. portion 12 opposite the said steamsupply, the valve portion 13 enlarged to full diameter of the valve andprovided with an abrupt shoulder below the reduced portion to receivethe steam pressure from said steam supply port and overcome thehesitating action of the valve.

6. In valve for steam hydraulic presses, the combination with a valvecasing having ports leading from the steam supply and to the liftingcylinder, and having a supplemental chamber at the upper end thereofprovided with a piston forming a dash-pot, of a main valve mounted inthe main valve chamber, a connection between said main valve and saidpiston and means for establishing communication between said valvecasing and said supplemental chamber.

7. In a valve for steam hydraulic presses, the combination with a valvecasing having a main valve chamber provided with ports leading from thesteam supply and to the lifting cylinder and to the exhaust, and havinga supplemental valve chamber, of a main valve mounted in said main valvechamber and controlling said main ports, and a valve stem carrying thesaid main valve and also carrying a supplemental valve cooperating inthe said supplemental chamber and acting as a dash pot to control thedownward movement of the valve.

8. In a valve for steam hydraulic presses, the combination with a valvecasing having a valve chamber provided'with ports leading from the steamsupply to the lifting Cylinder and to the exhaust, and having asupplemental valve chamber provided at its base with a choke port, of a'main valve controlling the ports of the main valve chamber and having astem carrying a supplemental valve operating in the supplemental valvechamber, and cooperating in the dash pot to control the downwardmovement of the main valve. V

9. Ina valve for steam hydraulic presses, the combination with avalve'casing having a valve chamber provided with a steam supplyporthaving downwardly extending port walls, and port leading to thelifting cylinvalve operating in the supplemental valve chamber andcooperating in the dash pot to control the downward movement of the mainvalve.

In testimony whereof I, the said ARNOLD,

P. BARK, have hereunto set hand ARNOLD P. BARK.

Witnesses 'H. F. VALENTINE, H. D. PENNINGTON.

